How many gallons in a cubic foot of water?

One cubic foot holds about 7.48 US gallons. So pool volume in gallons is the volume in cubic feet times 7.48.

Why do I need to know my pool volume?

Almost every chemical dose, from chlorine to salt to acid, is based on the number of gallons. Work out the volume once and reuse it for every dosing calculation.

Home / Pool Volume Calculator

Pool Volume Calculator

A pool volume calculator tells you how many gallons your pool holds. It takes the shape, the size, and the average depth, and returns the volume in gallons for rectangle, round, and oval pools. Pick a shape below and enter the size. Everything runs in your browser, with no signup.

Updated for 2026

Your pool

Pick a shape and enter the size. Results update instantly.

Shape

Length

Width

Shallow end depth

Deep end depth

Pool volume

Surface area

0 ft²

Average depth

0 ft

Volume

0 ft³

Liters

0 L

Use this volume in the chlorine and salt tools

Gallons for common pool sizes

Volume of a rectangular pool averaging 5 ft deep. Tap any row to load it.

Pool	Size	Avg depth	Gallons

How the pool volume is calculated

Pool volume is the surface area times the average depth, converted to gallons. The area depends on the shape, and the average depth is the shallow and deep ends averaged:

Gallons = Surface area × ( Shallow + Deep ) ÷ 2 × 7.48

One cubic foot holds 7.48 US gallons. A rectangle is length times width, a round pool is pi times the radius squared, and an oval is pi times half the length times half the width. For a pool with a constant depth, set the shallow and deep ends the same.

Worked example (Stand: 2026)

ShapeRectangle, 32 ft × 16 ft
Surface area (32 × 16)512 ft²
Depth3 ft shallow, 7 ft deep
Average depth ((3 + 7) ÷ 2)5 ft
Volume (512 × 5)2,560 ft³
Gallons (2,560 × 7.48)19,149 gal

Frequently asked questions

How many gallons is my pool?

Multiply the surface area by the average depth for cubic feet, then by 7.48 for gallons. The calculator above does this for rectangle, round, and oval pools.

How do I find the average depth?

Add the shallow end and deep end depths and divide by two. A 3 foot shallow and 7 foot deep pool averages 5 feet.

How many gallons in a cubic foot?

About 7.48 US gallons. So gallons equal the volume in cubic feet times 7.48.

Why does volume matter?

Nearly every chemical dose is based on gallons. Find the volume once and reuse it in the chlorine and salt calculators.

Does this calculator store my numbers?

No. Everything is calculated in your browser. Nothing you enter is sent to a server or saved.

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